Misuse, perceived risk, and safety issues of household insecticides: Qualitative findings from focus groups in Arequipa, Peru

Irrigation, migration and infestation: a case study of Chagas disease vectors and bed bugs in El Pedregal, Peru

BACKGROUND

The city of El Pedregal grew out of a desert, following an agricultural irrigation project in southern Peru.

OBJECTIVES

To describe infestation patterns by triatomines and bed bugs and their relationship to migration and urbanization.

METHODS

We conducted door-to-door entomological surveys for triatomines and bed bugs. We assessed spatial clustering of infestations and compared the year of construction of infested to un-infested households. To gain a better understanding of the context surrounding triatomine infestations, we conducted in-depth interviews with residents to explore their migration histories, including previous experiences with infestation.

FINDINGS

We inspected 5,164 households for Triatoma infestans (known locally as the Chirimacha); 21 (0.41%) were infested. These were extremely spatially clustered (Ripley's K p-value < 0.001 at various spatial scales). Infested houses were older than controls (Wilcoxon rank-sum: W = 33; p = 0.02). We conducted bed bug specific inspections in 34 households; 23 of these were infested. These were spatially dispersed across El Pedregal, and no difference was observed in construction age between bed bug infested houses and control houses (W = 6.5, p = 0.07).

MAIN CONCLUSIONS

The establishment of agribusiness companies in a desert area demanded a permanent work force, leading to the emergence of a new city. Migrant farmers, seeking work opportunities or escaping from adverse climatic events, arrived with few resources, and constructed their houses with precarious materials. T. infestans, a Chagas disease vector, was introduced to the city and colonized houses, but its dispersal was constrained by presence of vacant houses. We discuss how changes in the socioeconomic and agricultural landscape can increase vulnerability to vector-borne illnesses.

Perceptions of Problems with Household Insects: Qualitative and Quantitative Findings from Peri-Urban Communities in Arequipa, Peru

Vector-borne diseases continue to impose a major health burden on Peru and neighboring countries. The challenge of addressing vector-borne disease is compounded by changing social, economic, and climatic conditions. Peri-urban Arequipa is an important region to study insect infestations because of ongoing challenges with disease vectors such as triatomines and a variety of other insects. We conducted surveys (N = 1,182) and seven focus groups (average seven participants) in peri-urban Arequipa to explore knowledge of and perception toward various insects that infest the region. Focus group participants reported the presence of a wide variety of insects in and around the home, including disease vectors such as triatomines (also identified by 27.2% of survey households), mosquitoes, spiders, and bed bugs, as well as nuisance insects. Health concerns related to insects included vector-borne diseases, spider bites, allergies, and sequelae from bed bug bites, and hygiene concerns. A majority of participants in the quantitative surveys identified triatomines as the insect they were most worried about (69.9%) and could identify Chagas disease as a health risk associated with triatomines (54.9%). Insect infestations in peri-urban Arequipa present multiple burdens to residents, including injury and illness from triatomines and other insects, as well as potential mental and economic concerns related to insects such as bed bugs. Future initiatives should continue to address triatomine infestations through educational outreach and implement a more holistic approach to address the burden of both disease and nuisance insects.

High Prevalence of Chemical and Microbiological Drinking Water Contaminants in Households with Infants Enrolled in a Birth Cohort-Piura, Peru, 2016

Chemical and microbiological drinking water contaminants pose risks to child health but are not often evaluated concurrently. At two consecutive visits to 96 households in Piura, Peru, we collected drinking water samples, administered health and exposure questionnaires, and collected infant stool samples. Standard methods were used to quantify heavy metals/metalloids, pesticides, and Escherichia coli concentrations in water samples. Stool samples were assayed for bacterial, viral, and parasitic enteropathogens. The primary drinking water source was indoor piped water for 70 of 96 households (73%); 36 households (38%) stored drinking water from the primary source in containers in the home. We found high prevalence of chemical and microbiological contaminants in household drinking water samples: arsenic was detected in 50% of 96 samples, ≥ 1 pesticide was detected in 65% of 92 samples, and E. coli was detected in 37% of 319 samples. Drinking water samples that had been stored in containers had higher odds of E. coli detection (adjusted odds ratio [aOR]: 4.50; 95% CI: 2.04-9.95) and pesticide detection (OR: 6.55; 95% CI: 2.05-21.0) compared with samples collected directly from a tap. Most infants (68%) had ≥ 1 enteropathogen detected in their stool. Higher odds of enteropathogen infection at the second visit were observed among infants from households where pesticides were detected in drinking water at the first visit (aOR: 2.93; 95% CI: 1.13-7.61). Results show concurrent risks of exposure to microbiological and chemical contaminants in drinking water in a low-income setting, despite high access to piped drinking water.